TY - CHAP M1 - Book, Section TI - Hypokalemia A1 - Mount, David B. A2 - Jameson, J. Larry A2 - Fauci, Anthony S. A2 - Kasper, Dennis L. A2 - Hauser, Stephen L. A2 - Longo, Dan L. A2 - Loscalzo, Joseph PY - 2018 T2 - Harrison's Principles of Internal Medicine, 20e AB - Homeostatic mechanisms maintain plasma K+ concentration between 3.5 and 5.0 mM, despite marked variation in dietary K+ intake. In a healthy individual at steady state, the entire daily intake of potassium is excreted, ~90% in the urine and 10% in the stool; thus, the kidney plays a dominant role in potassium homeostasis. However, >98% of total-body potassium is intracellular, chiefly in muscle; buffering of extracellular K+ by this large intracellular pool plays a crucial role in the regulation of plasma K+ concentration. Changes in the exchange and distribution of intra- and extracellular K+ can thus lead to marked hypo- or hyperkalemia. A corollary is that massive necrosis and the attendant release of tissue K+ can cause severe hyperkalemia, particularly in the setting of acute kidney injury and reduced excretion of K+. SN - PB - McGraw-Hill Education CY - New York, NY Y2 - 2024/03/28 UR - accesspharmacy.mhmedical.com/content.aspx?aid=1178487194 ER -